81040933920 has 192 divisors, whose sum is σ = 271083770496. Its totient is φ = 20280360960.

The previous prime is 81040933913. The next prime is 81040933933. The reversal of 81040933920 is 2933904018.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2817210 + ... + 2845830.

It is an arithmetic number, because the mean of its divisors is an integer number (1411894638).

Almost surely, 2^81040933920 is an apocalyptic number.

81040933920 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81040933920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135541885248).

81040933920 is an abundant number, since it is smaller than the sum of its proper divisors (190042836576).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81040933920 is a wasteful number, since it uses less digits than its factorization.

81040933920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29003 (or 28995 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 39.

The spelling of 81040933920 in words is "eighty-one billion, forty million, nine hundred thirty-three thousand, nine hundred twenty".